Bladder Carcinoma In Situ: Single vs Multiple Lesions
Bladder carcinoma in situ (CIS) can present as either single or multiple lesions, though multifocal disease is more common and carries a worse prognosis. 1
Presentation Patterns of CIS
CIS typically manifests in three distinct clinical scenarios:
- Primary CIS occurs as an isolated finding without associated papillary tumors, representing less than 3% of all urothelial neoplasms 2
- Concurrent CIS appears simultaneously with papillary tumors and is always associated with multiple papillary lesions 3
- Secondary CIS develops during follow-up after treatment of previous bladder cancer 2, 4
Multifocality is the Rule, Not the Exception
The evidence strongly indicates that CIS is predominantly a multifocal disease:
- When CIS occurs concurrently with papillary tumors, it is always associated with multiple papillary lesions, never solitary ones 3
- Multifocal CIS lesions are identified as a particularly high-risk feature requiring more aggressive management 1
- The simultaneous presence of CIS can extend beyond the bladder, with prostatic urethral involvement found in 46% of patients and ureteral involvement in 74% 3
Clinical Implications of Lesion Multiplicity
Multifocal disease significantly impacts prognosis and treatment decisions:
- Multifocal CIS lesions are specifically categorized as high-risk disease that may warrant early cystectomy rather than repeat TURBT 1
- The presence of multifocal disease is one of the most important prognostic factors, along with prostatic urethral involvement and response to BCG therapy 2
- Progression to invasive cancer or death from disease is unusual in primary CIS but common when CIS is associated with other bladder cancers 4
Detection Challenges with Flat Lesions
CIS presents unique diagnostic challenges regardless of whether it is single or multiple:
- CIS is often missed by standard white light cystoscopy because it appears as flat lesions that can range from normal-appearing mucosa to areas indistinguishable from inflammation 1, 5
- Blue light cystoscopy detects CIS at significantly higher rates than white light cystoscopy (40.8% more CIS lesions detected; P<.001) 1
- Small or multifocal lesions are particularly difficult to detect with standard white light cystoscopy 1
Diagnostic Approach for Suspected CIS
When CIS is suspected or known, the following biopsy strategy is recommended:
- Multiple selective and/or random biopsies should be performed 1
- Additional biopsies adjacent to any papillary tumor are necessary 1
- Prostatic urethral biopsy should be considered given the high rate of prostatic involvement 1
Treatment Implications
The treatment approach does not fundamentally differ based on single versus multiple lesions, but multifocality affects prognosis:
- Standard therapy for CIS is resection followed by intravesical BCG therapy (category 1 recommendation), given once weekly for 6 weeks 1, 6
- For patients with multifocal high-risk disease, early cystectomy may be preferred over bladder preservation 1
- BCG instillation remains effective in 87% of CIS patients regardless of lesion number 3